SSRF Vulnerability in Sentry MCP Server Exposes Security Risks

• •CVE-2026-81421 allows SSRF attacks via unvalidated Axios requests.
• •36.7% of scanned MCP servers are vulnerable, with 41% lacking authentication.
• •Public exploit available, and maintainer has not responded for 46 days.

On July 12, 2026, researcher cccccccti disclosed a Server-Side Request Forgery (SSRF) vulnerability in the raw_sentry_api component of ddfourtwo/sentry-selfhosted-mcp, tracked as CVE-2026-81421. This vulnerability allows attackers to force Axios to call arbitrary endpoints, with a public exploit already available. As of August 27, 2026, the maintainer has not responded to the disclosure, leaving many systems exposed. Industry data indicates that 36.7% of 7,000 scanned MCP servers are vulnerable, and 41% lack authentication. Trend Micro identified 492 MCP servers exposed to the internet without authentication. This incident is linked to broader security issues in the Model Context Protocol (MCP) ecosystem, which has seen a shift in security responsibilities. The situation is exacerbated by a recent update that removed session-level security measures, creating new attack surfaces. The vulnerability poses significant risks for crypto infrastructure and related integrations.